There has been known a so-called inkjet recording apparatus that performs recording on a recording medium by ejecting fine droplets of ink from a plurality of nozzles formed in a head section.
A common inkjet recording apparatus is mounted with a plurality of head sections. This makes it possible to, in a case where a printing defect occurs in a particular position due to nozzle clogging of a head section, replace only the defective head section without replacing all of the head sections. Further, mounting the plurality of head sections in a direction of relative movement of a head section and a recording medium makes it possible to increase the resolution in a main scanning direction without reducing the recording speed or increase the recording speed while maintaining the resolution in the main scanning direction.
Incidentally, since, as mentioned above, a plurality of head sections are used in an inkjet recording apparatus, even a misalignment of one of the head sections, if any, causes a recording defect.
In a case where, as shown in FIG. 12, recording is performed on a recording medium X by five head sections H1 to H5 disposed to alternate with one another, a misalignment of the head H2 toward the head H1, if any, causes a dark portion M, which is an overlap of dots of applied ink, and an unprinted white streak portion N to appear in the recording on the recording medium X.
To address this problem, mechanisms for finely adjusting the position of a head section have been developed.
For example, there has been known an inkjet head position adjustment mechanism that adjusts the position of an inkjet head that is fixed on a carriage (see, for example, PTL 1). The position adjustment mechanism is configured such that an inkjet head 10 can be moved in +X, −X, +Y, and −Y directions on a reference surface of a pedestal 18 of a carriage by loosening a fixing screw and the inkjet head 10 can be fixed under pressure by tightening the fixing screw.
Further, there has been known an ink head (head section) position adjustment mechanism including: a first guide section formed to extend on a first side of a nozzle formation surface of an ink head in a longitudinal direction; a second guide section formed to extend on a second side of the nozzle formation surface of the ink head in the longitudinal direction; a contact member disposed to make contact with the first guide section; a top that spins; a top moving section for moving the ink head with the contact member as a fulcrum by means of a slide of the top and the second guide section on each other; and a graduated section that rotates by means of the spinning of the top (see, for example, PTL 2).
Further, there has been known a head unit in which a plurality of heads each having an arrangement of nozzles from which droplets are ejected are arranged on an array base member (see, for example, PTL 3). Each of the heads is held by a first plate member. The first plate member is held by a second plate member. The first plate member is rotatable on a Z axis with respect to the second plate member. The Z axis is perpendicular to a nozzle surface of the head and passes through a center position of a particular nozzle of the head. By screwing a screw into a screw hole of the array base member via a long hole of the second plate member and loosening the screw, the second plate member is made movable in an X-axis direction with respect to the array base member.